Encog.Engine.Util.ErrorCalculation.UpdateError C# (CSharp) Method

        public void UpdateError(double[] actual, double[] ideal)
        {
            for (int i = 0; i < actual.Length; i++)
            {
                double delta = ideal[i] - actual[i];

                if (Mode == ErrorCalculationMode.ARCTAN)
                    delta = Math.Atan(delta);

                this.globalError += delta * delta;
            }

            this.setSize += ideal.Length;
        }

        /// <summary>
        /// Calculate the error for this neural network. The error is calculated
        /// using root-mean-square(RMS).
        /// </summary>
        ///
        /// <param name="data">The training set.</param>
        /// <returns>The error percentage.</returns>
        public double CalculateError(IEngineIndexableSet data)
        {
            ErrorCalculation errorCalculation = new ErrorCalculation();

            double[] actual = new double[this.outputCount];
            IEngineData pair = BasicEngineData.CreatePair(data.InputSize,
                    data.IdealSize);

            for (int i = 0; i < data.Count; i++)
            {
                data.GetRecord(i, pair);
                Compute(pair.InputArray, actual);
                errorCalculation.UpdateError(actual, pair.IdealArray);
            }
            return errorCalculation.Calculate();
        }